Street-cleaning machine

ABSTRACT

A STREET-CLEANING MACHINE OF THE SELF-PROPELLED VEHICLE TYPE WHICH INCLUDES FRAME-MOUNTED BRUSHES POSITIONED FOR CONTACT WITH THE STREET, A VACUUM ASSEMBLY MOUNTED TO THE REAR OF THE BRUSHES TO RECEIVE DEBRIS THEREFROM, AND A DEBRIS COLLETION BIN CARRIED ON THE FRAME AND RECEIVING DEBRIS DISCHARGED FROM THE VACUUM ASSEMBLY. THE COLLECTION BIN HAS AT LEAST ONE AIR OUTLET OPENING THEREFROM AND HAS SCREEN AND BAFFLE MEANS POSITIONED BETWEEN THE INTERIOR OF THE BIN AND SUCH DISCHARGE OPENINGS. A PLURALITY OF CLOTH AIR FILTERS ARE CONNECTED TO THE OUTLET OPENINGS AND EACH IS FORMED TO CONTAIN A PLURALITY OF VERTICALLY EXTENDING CHANNELS THROUGH WHICH FINE DIRT AND DUST ARE PRECIPITATED INTO A DUST CHAMBER LOCATED ABOVE THE COLLECTION BIN.

United States Patent [72] Inventor wernerw Young 3 0 1 N. E. 13th Street Oklahoma City, Okla. [211 Appl. Nov 855,090 [22] Filed Sept. 4, 1969 [45] Patented June 28, 1971 [54] STREET-CLEANING MACHINE 7 Claims, 6 Drawing Figs.

[52] US. Cl 15/352, 15/353, 55/319, 55/324, 55/334, 55/341, 55/385 [51] Int.Cl E01h 1/08 [50] Field of 15/340, 352, 353, (D163); 55/320, 321, 341,366, 368

[56] I References Cited I UNITED STATES PATENTS 2,133,141 10/1938 Helm-Hansen 15/D1G.8 2,171,909 9/1939 Berman 55/368 g;,174,73 q 10/1939 White ss assx 3,242,151 3/1966 Young Primary Examiner-Walter A. Scheel Assistant ExaminerC. K. Moore Attorney-Dunlap, Laney, Hessin and Dougherty ABSTRACT: A street-cleaning machine of the self-propelled vehicle type which includes frame-mounted brushes positioned for contact with the street, a vacuum assembly mounted to the rear of the brushes to receive debris therefrom, and a debris collection bin carried on the frame and receiving debris discharged from the vacuum assembly. The collection bin has at least one air outlet opening therefrom and has screen and baffle means positioned between the interior of the bin and such discharge openings. A plurality of cloth air filters are connected to the outlet openings and each is formed to contain a plurality of i/ertically extending channels through which fine dirt and dust are precipitated into a dust chamber located above the collection bin.

STREET-CLEANING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to machines which are useful in cleaning streets, highways, airport runways and the like. More particularly, but not by way of limitation, this invention relates to a self-propelled machine which has mounted thereon rotating cleaning brushes and a pneumatic system for cooperation with such cleaning brushes to remove debris, dust and litter from streets.

2. Description of the Prior Art In my US. Pat. No. 3,406,423, l have disclosed a selfpropelled street-cleaning machine which is highly effective in operation and which can be efficiently used to remove dust and litter from streets and highways without the necessity to spray water and other mud-forming material on the dust and litter. The present invention constitutes an improvement over the street-cleaning apparatus depicted and described in my US. Pat. No. 3,406,423, the improvement which is provided by the present invention residing primarily in the manner of filtering and removing dust and lint from air drawn into the system. As a result of such improvement, air discharged from the system is very clean, and a major portion of any entrained solid material is removed from the circulating air.

SUMMARY OF THE INVENTION Broadly described, the street-cleaning apparatus of the present invention comprises a horizontally disposed frame of the type used in trucks or the like, such frame having conventional left and right sides and front and rear ends. At least one brush is rotatably mounted on the lower or under side of the frame for scouring the surface of the street or highway to remove dust 'and debris therefrom. A vacuum assembly is mounted on the frame to the rear of the brushes and includes conduit means which extends forwardly toward the brushes, and has secured to the forward end thereof, a nozzle which is positioned to receive dirt and debris directly from the brushes as the brushes function in securing the street or runway.

A collection bin is mounted toward the rear end of the frame and is provided with an inlet opening and at least one outlet opening. Suitable blower means is mounted on the frame and is connected to the vacuum assembly and to the bin for drawing air into the vacuum assembly through its nozzle and passing this air from the vacuum assembly through the inlet opening into the bin. A dividing panel means is preferably secured in the bin for dividing this enclosure into a first chamber which is disposed toward one side of the frame, and a second chamber which is disposed toward the other side of the frame.

Screen and baffle means is provided between the interior of the collection bin and the outlet openings therefrom so that, as air is circulated from this bin toward and through the outlet openings, substantially all of the significantly sized particulate material such as dust, debris, paper, dirt and the like are removed from the air and are deposited in the bin for subsequent disposal. Secured to each of the air outlet openings from the bin is a cloth air filter which is formed so that air moves upwardly in the filter, and entrained dirt and dust is precipitated downwardly toward one or more discharge openings in the lower portion of each of the cloth air filters. The cloth air filters are each divided into a plurality of vertically extending channels which intersect a horizontally extending channel at the top of the filter, and these vertically extending channels converge to the discharge openings in the lower portion of each filter.

From the foregoing broad and general description of the invention, it will have become apparent that it is an important object of the invention to provide a highly efficient streetcleaning apparatus which is effective to remove substantially all of the entrained dust and solid particulate material which may be moved into and through the apparatus by means of a strong blower system provided in conjunction with other portions of the apparatus.

An additional object of the invention is to provide a compact and relatively economically constructed street or highway-cleaning apparatus which can be utilized for thoroughly cleaning all types of roads and highway surfaces.

An additional object of the present invention is to provide an improved, self-propelled street-cleaning machine which discharges relatively clean or pure air which has been passed through the apparatus in order to convey dirt and debris to collection devices therein.

In addition to the foregoing disclosed objects and advantages, additional objects and advantages will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation view of a self-propelled streetcleaning machine constructed in accordance with the invention.

FIG. 2 is an enlarged top elevation view, showing partly in section and partly in elevation a suction nozzle and a conduit system forming a part of the vacuum assembly utilized in the invention.

FIG. 3 is a rear elevation view of the self-propelled streetcleaning machine of the invention showing the interior of the collection bin used in the street-cleaning apparatus as it appears when a hinged rear door used for closure of the bin has been removed for purposes of illustration.

FIG. 4 is an enlarged detail view, partially in section, and partially in elevation, showing certain baffle, screening and filter elements utilized in a preferred embodiment of the present invention.

FIG. 5 is a plan view of the rear portion of the street-cleaning machine illustrated in FIG. ll.

FIG. 6 is a sectional view taken along line 6-6 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings, and to FIG. 1 in particular, a street-cleaning machine constructed in accordance with the invention is depicted, and is designated generally by reference numeral 10. The street-cleaning machine 10 includes a selfpropelled truck 12 having a cab 14 mounted on a chassis or frame 16. The frame 16 is provided in a conventional manner with a front set of tires and wheels 18 and a rear set of tires and wheels 20 which serve to support and propel the truck 12. Mounted on the rear of the frame 16 is a collection bin 22. The collection bin 22 is mounted for pivotal movement in the manner conventional with dump trucks or the like. The collection bin 22 includes a hinged door 24 connected to the back of the collection bin for pivotation about a horizontal axis, sidewalls 26 and 28, a bottom wall 30, a top wall 32, and a forward wall 34.

The collection bin 22 is provided with a plurality of air outlet openings, these being designated by reference numerals 36a36 and 38a38h (see FIGS. 4 and 6). The series of air outlet openings 36a-36h extend through the right side of the top wall 32 for connection to a plurality of cloth air filters in a manner hereinafter described. Similarly, the air outlet openings 38a-38h are provided through the left side of the top wall 32 for connection to a plurality of cloth air filters. Positioned inwardly of the openings 36a36h in the top wall 32 are two fore-and-aft aligned series of air discharge openings to receive air discharged from the cloth air filters, these openings being designated by reference numerals 40a- -40h and 4212-4211, respectively. Similarly, two series of fore-and-aft aligned air discharge openings are provided inwardly of the air outlet openings 38a-38h, and these series of openings are designated by reference numerals 44 a44h and 4641-46, respectively.

In the forward wall 34 of the collection bin 22, a large air inlet opening 50 is provided for the purpose of admitting air to the interior of the collection bin from a duct 52. The duct 52 is rigidly secured to the forward wall 32 of the collection bin 22, and carries at its free end a flange 54 which permits it to sealingly engage a blower discharge duct 56 (see FIG. 1) forming a portion of a blower assembly mounted on the frame 16 ahead of the collection bin 22. The blower assembly in cludes a centrifugal blower (not shown) which is driven by a suitable power transmission shaft 58 from the engine of the truck 12.

A vacuum assembly, designated generally by reference numeral 60, is connected to the under or lower side of the framework 16 and its details of construction are best illustrated in FIGS. 1 and 2. The vacuum assembly 60 includes an elongated debris pickup nozzle 62 which is provided with an elongated lift bar 64 secured to the upper side thereof and an elongated opening (not shown) in the lower side thereof. The pickup nozzle 62 is connected at its opposite ends through a pair of rearwardly extending ducts 66 to a blower inlet duct 68. The ducts 66 are connected through movable joints 70 to the blower inlet duct 68 so that the pickup nozzle 62 can be elevated by pivotation about a horizontal axis, using a hydraulic piston and cylinder assembly 72 which is connected between the frame 16 and the lift bar 64.

The blower inlet duct 68 is connected in a suitable manner to the blower assembly so that air is drawn from the blower inlet duct 68 through the blower and discharged through the blower discharge duct 56 into the duct 52. A pair of rotatably driven brushes 76 are mounted below the left and right sides of the cab 14 of the truck 12 and just ahead of the pickup nozzle 62. The brushes 76 are mounted to be lowered into scouring contact with the surface of a roadway. Additional details as to the construction of the vacuum assembly 60 and brushes 76 used in the illustrated embodiment of the present invention can be ascertained by reference to my U.S. Pat. 3,242,52 l, the teachings of which are incorporated herein by reference.

The collection bin 22 is divided into a left collection chamber and a right collection chamber by a longitudinally extending partition plate or wall 78 which extends upwardly from the bottom wall 30 of the collection bin 22 to the center of a curved, generally horizontally extending deflection plate 80. The deflection plate 80 is located so that it terminates just below the air inlet opening 50 formed in the forward wall 34 of the collection bin 22 as best illustrated in FIG. 3. Extending downwardly and slightly inwardly from the opposed longitudinal edges of the deflection plate 80 are a pair of air-deflecting baffles 82 and 84. A substantially horizontally extending main baffle plate 86 is secured to the forward wall 32 of the collection bin 22 so as to intersect this wall immediately above the air inlet opening 50 and to extend rearwardly in the collection bin in substantial parallelism with the deflection plate 80. It will be noted that the main bafile plate 86 does not extend completely across the collection bin 22, but instead terminates in longitudinal edges 88 (see FIG. 4) which are spaced inwardly from the sidewalls 26 and 28 of the collection bin 22. A pair of elongated dust chamber defining vertical walls 90 and 92 are secured to the upper surface of the main baffle plate 86 and are horizontally spaced from each other and extend from the front wall 34 of the collection bin 22 to the rear thereof.

Screen and baffle means is located in the upper and outer comer of each of the collection chambers formed in the collection bin 22 by the partition plate 78. The screen and baffle means is identical in the case of each of the two collection chambers and one of these means is shown in FIG. 4. Each screen and baffle means includes a downwardly depending bafi'le plate 96 which is secured at its upper longitudinal edge to the main baflle plate 86. It will be noted in referring to FIG. 4 that the downwardly depending baffle plate 96 is spaced inwardly from the longitudinal edge 88 of the main baffle plate 86, and thus is also spaced a substantial distance inwardly from the sidewall 28 of the collection bin 22. An arcuate, longitudinally extending screen 98 or other permeable filter member extends between the lower edge of the downwardly extending baffle plate 96 and the lower edge of an upwardly extending, inclined deflection plate 100. Both the screen 98 and the inclined deflection plate 100 extend over the entire length of the collection bin 22 as described in my U.S. Pat. 3,406,423.

A second elongated, arcuately cross-sectioned screen 102 is secured to the lower end of the downwardly extending baffle plate 96, and is bent outwardly therefrom toward the upstanding deflection plate 100. An elongated curved baffle plate 104 is secured at one of its longitudinal edges to the upper edge of the screen 102, and at its other or outermost edge to an upper portion of an elongated panel 106. The lower edge of the elongated panel 106 is secured to the sidewall 28 of the collection bin 22 by means of a series of spacers 108 so that air can flow between the panel 106 and the sidewall, and from this space, into the right collection chamber of the collection bin 22. It will also be noted in referring to FIG. 4 that the upstanding baffle plate 100 is secure at its lower end by suitable spacers 109 to the lower end of the panel 106. This permits air to flow between the upstanding baffle 100 and the panel 106 into the right collection chamber of the collection bin 22.

The upper end of the panel 106 projects above the longitudinal edge 88 of the main baffle plate 86 and is spaced outwardly from this edge. An upstanding screen 110 or perforated member is spaced inwardly a small distance from the longitudinal edge 88 of the main baffle plate 86 and extends upwardly from the main baffle plate and is secured at its upper end to an elongated arcuate plate 112. All of the screens, baffle plates and panels included in the screen and baffle means located in the upper, outer comers of each of the two collection chambers in the collection bin 22 extend over the entire length of the collection bin in a longitudinal direction.

Secured to the top wall 32 of the collection bin 22 is a filtersupporting rack, such rack being best illustrated in FIGS. 1, 3, 4 and 5 and including vertical stanchions 114, 116, 118, located at the four corners of the bin 22 and a pair of vertically extending central stanchions 122 and 124 disposed between the sidewalls 26 and 28 at the back of the bin 22 and at the front of the bin. The vertically extending stanchions support a pair of longitudinally extending side rails I26 and 128 (see FIGS. land 5), a pair of transverse rails 130 and 132, and a pair of centrally located longitudinally extending rails 134 and 136 which extend substantially parallel to the side rails 126 and 128.

The filter supporting rack is used to support a plurality of cloth air filters above the collection bin 22 in the positions illustrated in the drawings. In the illustrated embodiment of the invention, sixteen of such air filters are shown, these being grouped in two aligned rows containing eight air filters in each row. The air filters positioned above the right side of the collection bin 22 are designated by reference numerals 138a- -l38h and those which are in the group positioned above the left side of the collection bin are designated by reference numerals I40a140h. A greater or a smaller number of cloth air filters may be employed if desired.

Each of the cloth air filters 138a-138h and 140a-l40h are preferably constructed of a heavy cloth material such as mill duck and each of the filters is suspended from the filtersupporting rack by straps 142 and 144 located at the opposite upper comers of each air filter. These straps can be attached by wire or any other suitable means to the adjacent rails 126, 128, 134 or 136. Each of the cloth air filters 138a138h and l40a-l40h are constructed in the manner best illustrated in FIGS. 4 and 6. Thus, each of the cloth air filters includes a series of vertically extending channels l46a-l46i which extend upwardly toward a horizontally extending transverse channel 150. The channels are formed and defined by stitching opposite sides of the cloth air filter to each other. It will be noted in referring to FIG. 4 that the channel 146a is positioned adjacent one vertically extending lateral edge 152 of the cloth air filter, and communicates at its upper end with one end of the horizontally extending channel 150. It will also be noted that all of the channels 146b-l46h also communicate at their upper ends with the horizontally extending channel 150. Adjacent an inboard end or terminal side edge 154 of each cloth air filter 1138a, a vertically extending channel l46i is located and is closed at its upper end. It will be noted that the vertically extending channels 146b-l46e all converge at their lower ends into an inverted, conically shaped lower portion of the cloth air filter, and that this inverted, conically shaped lower portion is secured to the top wall 32 around one of the air discharge openings 40a. This discharge opening 400 is, as has been previously described, located inwardly of the vertical wall 90 which, with the vertical wall 92, the top wall 32 and the main baffle plate 86 form the dust collection chamber. in similar manner, the vertically extending channels l46fl46i converge to and communicate with, an inverted, conically shaped lower portion of the cloth air filter which is connected to a flange surrounding the air discharge opening 42a which opens into the dust collection cham ber. The vertically extending channel 146a is connected at its lower end to a flange which surrounds the outlet opening 36a formed through the top wall 32 of the collection bin 22, and receives air after it has passed through the screen and baffle means as hereinafter described.

Operation In the operation of the street-cleaning machine of the present invention, the blower assembly of the apparatus is energized by engaging the power transmission shaft 58 with the engine of the self-propelled truck 12 to receive power therefrom. When the blower assembly is thus energized to drive a centrifugal blower or other suitable fan or blower in rotation, air is drawn through the vacuum assembly so that a strong draft of air moves into the opening formed on the lower side of the elongated debris pickup nozzle 62. Simultaneously with this action, the brushes 76 are driven in rotation to loosen and remove caked dirt, paper or other debris which may rest upon or be adhered to the surface of the street. The dust or other debris is given a rearward movement relative to the selfpropelled vehicle by both the forward movement of the vehicle and the directional rotation of the brushes 76. The dust and debris thus moves toward, and is ultimately sucked into, the vacuum assembly 60 through the opening in the pickup nozzle 62, and from such opening, moves into the rearwardly extending ducts 66. The dust and debris then pass through the blower inlet duct 68, the blower discharge duct 56 and the duct 52 which is connected to, and moves with, the pivotally mounted collection bin 22.

The dust and debris from the duct 52 pass through the air inlet opening 50 to the interior of the collection bin 22 and move rearwardly therein between the deflection plate 80 and the main baffle plate 86. The air and debris then move downwardly between the respective air directing baffles 82 and 84 and the baffles 96 into the collection chambers formed on each side of the collection bin 22 by the partition plate 78.

As the dust laden air enters the right and left collection chambers of the collection bin 22, it has imparted thereto, a swirling or rotating motion which tends to deposit out, or effectively centrifuge therefrom, a substantial portion of the larger particles of dirt, paper and other debris which are carried in the moving air stream. The swirling or rotational movement of the air entering the right and left collection chambers carries the air close to the bottom wall of the collection bin 22, then up against the partition plate 78, and then through a circuitous path back toward the lower and outside corner of each collection chamber.

The air which accumulates in the lower and outer corners of each of the collection chambers then moves upwardly through the respective arcuate, longitudinally extending screens 98 which form a portion of the screen and baffle means disposed in the upper and outer comers of each of the collection chambers and interposed between the respective collection chambers and the air outlet openings 36a36h and 38a38h. As the air moves through the screen and baffle means, a substan tial portion of the intermediate and fine-sized dirt and debris is removed therefrom in a manner described in detail in my U.S.

Pat. 3,406,423. Finally, the air carrying only fairly minute particles of dust and dirt passes through the air outlet openings 36a-36 and 3811-38]: and into the several cloth air filters l38a138h and al40h. As the air passes through the respective outlet openings 36a-36h and 38a-38h, it initially enters the vertically extending channels 146a of the cloth air filters. Air passes upwardly in this vertically extending channel until it reaches the top of the respective cloth air filter, at which point it impinges against the top wall of the respective cloth air filter forming the top side of the horizontally extending channel 150. As the result of the upward velocity of air in the respective cloth air filters, a portion of this air passes out of the top sides of the cloth air filters. At the same time, the larger portion of the air is deflected into a horizontal flow within the respective horizontally extending channel 150. Upon this directional change of the air flow, the dirt particles carried thereby tend to be cast out of the air and to drop downwardly in the vertically extending channels 146b-l46h. A part of the airstream also flows downwardly in these channels and aids in propelling the dirt particles downwardly. That portion of the air which passes through the air permeable upper side of each of the cloth air filters is relatively dust free as a result of the very efficient filtering action of each of the cloth air filters. Any of the residual air which continues to flow through the horizontally extending channel 150 and downwardly through the vertically extending channel 146'! can flow upwardly in the terminal, vertically extending channel 146i, and will be passed out through the permeable filter cloth at the top of this channel.

It is important to note that in the action of each of the cloth air filters, the air flow is directed so that the dust and dirt particles are precipitated downwardly by a directional change of the air flow while the air is permitted to move upwardly out of the upper portion of the filter. Thus, there is little tendency of the dirt particles to clog or block the pores or minute openings in the cloth on the upper side of the horizontally extending channel 150, and this area remains relatively dirt free over an extended operating period. Thus, the filter does not present the problem encountered with many types of cloth air filters of differing construction which simply strain the dirt or dust particles from the air as the air moves through the pores of the filter with the result that, in a relatively short time, the filter becomes blocked or clogged and must be replaced or cleaned.

Although a preferred embodiment of the invention has been herein described in order to illustrate the basic principles upon which the invention is bottomed, it is to be understood that various changes and innovations can be effected in the illustrated and described structure without departure from these principles. Changes and innovations of this type are therefore deemed to be circumscribed by the spirit and scope of the invention.

lclaim:

l. Street-cleaning apparatus comprising:

a horizontally disposed frame;

at least one brush rotatably mounted on the lower side of the frame for scouring the surface of a roadway;

a collecting bin mounted on said frame and having an inlet opening, at least one outlet opening, and a plurality of discharge openings therein, said collection bin further having sidewalls and a top wall containing said outlet openings and said discharge openings;

means in said collection bin defining a dust chamber adjacent said top wall, said dust chamber having said discharge openings opening thereinto;

means for drawing debris from adjacent said brushes into said collection bin;

screen and baffle means positioned within said collection bin over said outlet openings for removing relatively large solid particles from air moving from said collection bin into said outlet openings;

at least one cloth air filter outside said collection bin each connected to one of said outlet openings and to one of said discharge openings, each of said cloth air filters having a plurality of vertically extending channels formed therein, and having a horizontally extending channel extending across and intersecting the upper ends of said vertically extending channels.

2. Street-cleaning apparatus as defined in claim 1 wherein each of said cloth filters has one of said vertically extending channels connected at its lower end to one of said outlet openings, and has all of the other of said vertically extending channels connected to a plurality of said discharge openings.

3. Street-cleaning apparatus as defined in claim 1 wherein each of said cloth air filters has a pair of substantially vertically extending side edges, and said one vertically extending channel is adjacent one of said side edges, and wherein each of said cloth air filters is further characterized in having a terminal, vertically extending channel adjacent the other of the side edges of the respective filter, said terminal, vertically extending channel having a closed upper end and a lower end connected to one of said discharge openings.

4. Street-cleaning apparatus as defined in claim I wherein each of said cloth air filters has at least one inverted conically shaped lower portion, each of said inverted conically shaped lower portions being connected to one of said discharge openings and receiving the lower end of at least a portion of said vertically extending channels.

5. Street-cleaning apparatus as defined in claim 1 and further characterized to include a filter-supporting framework secured to the upper side of said collection bin and supporting said cloth air filters above said top wall.

6. Street-cleaning apparatus as defined in claim 3 wherein each of said cloth air filters has at least one inverted conically shaped lower portion, each of said inverted conically shaped lower portions connected to one of said discharge openings and receiving the lower ends of at least a portion of said vertically extending channels.

7. Street-cleaning apparatus as defined in claim 6 and further characterized to include a filter-supporting framework secured to the upper side of said collection bin and supporting said cloth air filters above said top wall. 

